There are many devices that use electricity as their energy source, but due to their mobility needs use batteries as their energy supply. Such energy consumers vary and may include without limitation medical devices/appliances (e.g. hearing aid devices), computer peripheral devices (e.g., mouse, keyboard, and the like), remote controllers (e.g., for televisions, set-top boxes, air conditioning devices, and suchlike), shaving devices, and the like. Such consumer devices typically need replacement/recharging of their batteries from time to time.
Regular batteries are not reusable, their improper disposal is a source of pollution, and their replacement may be tiresome. Therefore many of the consumer devices nowadays employ rechargeable batteries, where recharging is implemented by connecting a battery to a specific charging device, which typically has a design dedicated for connecting and charging a specific battery/device or a specific type of battery/device. Although this approach reduces the use of regular non-reusable batteries, it led to a situation where each rechargeable consumer device requires a specific dedicated charger for charging its batteries.
One possible approach to preclude the need for a plurality of dedicated chargers for the various rechargeable consumer devices is based on wireless charging techniques. For example, RF radiation energy available in surroundings of an electric device to be charged (e.g., RF from cellular networks and phones, as well as from other sources), may generally be utilized for recharging a small battery of an electric device. Such RF wireless charging techniques are known as RF energy harvesting. Typically, with ambient RF energy harvesting, there is no enough energy available to effectively recharge the batteries for their continuous uninterrupted use.
Another known approach is described for example in the following publications: U.S. Pat. No. 6,967,462 describes charging of devices by microwave power beaming. This technique is aimed at providing wireless, charging power and/or primary power to electronic/electrical devices whereby microwave energy is employed. Microwave energy is focused by a power transmitter comprising one or more adaptively-phased microwave array emitters onto a device to be charged. Rectennas within the device to be charged receive and rectify the microwave energy and use it for battery charging and/or for primary power. A locator signal generated by the device to be charged is analyzed by the system to determine the location of the device to be charged relative to the microwave array emitters, permitting the microwave energy to be directly specifically towards the device to be charged. Backscatter detectors respond to backscatter energy reflected off of any obstacle between the device to be charged and the microwave array emitters. Power to any obstructed microwave array emitter is reduced until the obstruction is removed. Optionally, data can be modulated onto microwave energy beams produced by the array emitters and demodulated by the device, thereby providing means of data communication from the power transmitter to the device. Similarly, data can be modulated onto the locator signal and demodulated in the power transmitter, thereby providing means of data communication from the device to the power transmitter.
U.S. Pat. No. 6,127,799 describes a method and apparatus for wireless powering and recharging. According to this technique, an arrangement is provided for charging a charge storage device by placing the charge storage device in an RF or microwave radiation field. One or more antennas which receive the radiated RF electromagnetic field are placed on the charge storage device. Rectifiers connected to the antennas rectify the received RF electromagnetic field and produce a DC output current which is used to charge the charge storage device. The charge storage device may be a battery or a capacitor and may form an integral part of an electronic device. The same RF field that charges the charge storage device can also be employed to communicate data to transponders which may be associated with computing devices.